This present disclosure relates generally to techniques for performing wellsite operations. More specifically, the present disclosure relates to techniques for preventing blowouts involving, for example, a blowout preventer, ram assembly, a door assembly, and/or a lock.
Oilfield operations may be performed to locate and gather valuable downhole fluids. Oil rigs are positioned at wellsites, and downhole tools, such as drilling tools, are deployed into the ground to reach subsurface reservoirs. Once the downhole tools form a wellbore to reach a desired reservoir, casings may be cemented into place within the wellbore, and the wellbore completed to initiate production of fluids from the reservoir. Downhole tubular devices may be positioned in the wellbore to enable the passage of subsurface fluids to the surface.
Leakage of subsurface fluids may pose an environmental threat if released from the wellbore. Equipment, such as blow out preventers (BOPs), may be positioned about the wellbore to form a seal about a tubular therein to prevent leakage of fluid as it is brought to the surface. BOPs may have selectively actuatable rams or ram bonnets, such as pipe rams or shear rams, that may be activated to seal and/or sever a tubular in a wellbore. Some examples of BOPs are provided in U.S. Patent/Application Nos. 20110000670; U.S. Pat. Nos. 7,814,979; and 7,367,396.
It may be desirable to provide BOPs with various features, such as seals, ram blocks, doors and/or lock mechanisms, etc., for use in wellsite operations. Examples of BOPs and/or features may be provided in patent application Ser. Nos. 13/018,217 (not yet published at the time of filing), US2010/0243926, US2011/0012311, U.S. Pat. Nos. 5,897,094, 7,044,430, 7,051,989, 5,575,452, WO 2012/012192, WO 2012/012193, U.S. Pat. Nos. 7,195,224 and 7,798,466.